Iron as a mixture, and a Compound:

One very unique thing about iron and all the other elements is that they could be mixed with another element on periodic table, to give you something completely different from the two basic elements. Usually when that happens, the original elements physical, and chemical property change in to something else. When you do that you just created something different, or a compound from two different elements, with different properties.

 When iron is in a mixture it has been involved in a physical change unlike a compound. When iron is mixed with other elements as a mixture, it is possible that you can get the original elements back. They create some kind of new substance. Ex: water when mixed with salt the salt dissolves into the water. That is called a mixture, and it is easy to get the salt back from the water by Boiling it.

One example of iron as a compound is FeO. Fe stands for iron as on the periodic table. O is also an element on the periodic table. O stands for Oxide. The two elements have to go throw a chemical change. When the two elements are combined they make a compound called FeO.